The present disclosure relates to a stator assembly method and a stator assembly apparatus, and in particular to a stator assembly method and a stator assembly apparatus in which coils are moved from the inner peripheral side toward the radially outer side of a stator core to be inserted into slots.
Hitherto, there has been known a stator assembly method in which coils are moved from the inner peripheral side toward the radially outer side of a stator core to be inserted into slots. Such a stator assembly method is disclosed in Japanese Patent Application Publication No. 2011-193597 (JP 2011-193597 A), for example.
JP 2011-193597 A discloses a stator assembly method in which a jig is disposed on the inner peripheral side of a stator core with coils mounted to holding grooves of the jig with the same pitch as that of slots of the stator core and the coils are moved radially outward to be inserted from the holding grooves into the slots. More particularly, the entire coils are moved from the holding grooves toward the slots (radially outward) with a pushing device pressing coil end portions of the coils radially outward while a pressing device is pressing the coil end portions of the coils in the axial direction to increase the width of the coils, which are annular, in the circumferential direction (while collapsing the coil end portions in the axial direction).
With the assembly method according to JP 2011-193597 A, it is difficult to control the direction in which the coil end portions are collapsed when the pressing device presses the coil end portions in the axial direction, and therefore the shape of the coil end portions after the assembly disadvantageously tends to be non-uniform because the coil end portions collapse so as to fall in the radial direction. Individual coils have a dimensional difference due to manufacturing variability. Therefore, with the assembly method according to JP 2011-193597 A, the pressing device may disadvantageously collapse (deform) coils having relatively large coil end portions more than necessary. With the assembly method according to JP 2011-193597 A, in addition, the entire coil end portions are deformed by the pressing device so as to be collapsed, and therefore the coils (coil end portions) disadvantageously tend to be damaged when pressed against the stator core.
Therefore, from the viewpoint of suppressing variations in shape of the coil end portions and suppressing damage to the coil end portions, it is desirable if the coils can be assembled to the stator core without pressing the coil end portions in the axial direction to be deformed (collapsed) during assembly.